The explosion lasted for more than two hours, giving many amateur astronomers time to catch the eruption in action. Other than photo-ops, however, this explosion will probably not affect Earth much. The cloud ejected by the blast is not heading our way.

SUBSIDING PERSEIDS: Earth is exiting the debris stream of Comet Swift-Tuttle, source of the Perseid meteor shower. According to the International Meteor Organization, dark-sky observers are now counting fewer than 20 to 30 Perseids per hour, a sharp drop from the peak of 100 per hour on August 13th. The show is essentially over, except for some lingering debris:

"At about 1:05 a.m. PDT on August 13th, a bright Perseid raced over Borrego Springs, California, illuminating our desert surroundings," reports photographer Dennis Mammana. "We could see the fireball's debris for several minutes as it twisted in the upper atmospheric winds--very pretty!"

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.